In an age when nukes existed but pocket calculators did not, the potential damage of a nuclear strike could be quantified using cardboard slide rules like this one.

Using data gleaned from the book The Effects of Nuclear Weapons, these circular "computers" could calculate weapons effects like yield and range when the big one dropped. The instrument pictured here is circa 1960, and is one of several pictured in a gallery on the Oak Ridge Associated Universities website. [ORAU via Dinosaurs and Robots via Boing Boing]